i downloaded version 2.5 of your plugin, installed and activated. however i am unable to use it due to missing fields on the 'send email to users' page.
the options available are:
Mail format
Send From (name)
Send From (email)
Send To (use CTRL key to select/deselect multiple items)
this is all. there are no text areas for subject or body text and no send button. if my description is inadequate please let me know and i will send a screen shot.